Test Fluids

Test fluids are a simple and inexpensive way to estimate surface energy and require no special training. They are available in graduated energy level sets in the form of bottled ink with brush applicator or in the form of marker pens.

In both methods increasing graduations (energy level) of the test fluid are simply drawn over the surface in turn. Low energy level fluids will bead up on the surface indicating that the surface energy is lower than that of the fluid used. When a particular fluid no longer forms beads but instead spreads evenly on the surface, the surface energy is approximately equal to that of the fluid.

Surface energy is usually given in units of dynes/cm or mN/m and the test fluids are available in blue, red or green colour. Blue fluids are formamide based (toxic) and are formulated to DIN ISO8296 which means that the results are comparable between different manufacturing sites or laboratories. Red and green fluids are alcohol based (non-toxic) and so strictly speaking not comparable between sites although usually absolutely fine for most instances.

Individual Bottles and Sets

Individual Test Fluid BOTTLES

  Individual 12ml Test Bottles with Brush Applicator Table 1
  Green   Red
  Range   Increment   Range   Increment   Range   Increment
18-28mN/m 2mN/m 24-72mN/m 2mN/m 34-46mN/m 2mN/m
30-46mN/m 1mN/m
48-72mN/m 2mN/m
105mN/m n/a

Test Fluid Bottles Sets

Available in sets containing six(blue) or seven (green and red) individual bottles in a sturdy case.
Our most popular sets are shown in the table below.


  Individual 12ml Test Bottles with Brush Applicator in Sturdy Case                                        Table 2
  Blue   Green   Red
28, 38, 56, 64, 72 & 105 mN/m 24, 30, 36, 42, 48, 58 & 72 mN/m 34, 36, 38, 40, 42, 44 & 46 mN/m



Test Pens

Easy-Test Pens

Easy-Test Pens are filled with 100ml fluid with any energy level from the green fluid range in table 1 above.

Quick-Test Pens

The Quick-Test pens are used as a quick quality test of whether or not a part has been plasma treated. They are refillable and come with a single ‘setting’
of 38 mN/m

Test Pen Sets

Henniker supply sets of surface energy test pens, available with graduated levels of surface tension. The pen is applied to the surface under study and a simple visual observation of wettability is made. Using pens of increasing  surface tension provides a rapid identification of the approximate level of the surface energy of the sample,

Surface energy is normally measured in energy units called dynes/cm or mN/m. Our Surface Energy Test Pens Set contains individual pens covering the range 34 mN/m to 72 mN/m in 2mN/m increments.



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